Gardeners can enjoy a second flush of wisteria flowers this summer by using tomato feed, according to gardening expert Ish. The Japanese variety, wisteria alba, produces white blooms and can flower twice a year, unlike the classic purple wisteria which blooms once.
Ish, a TikTok creator, explained that wisteria alba is slow-growing but becomes “incredibly vigorous” after two to three years, growing up to one to three metres annually. To encourage blooming, the plant needs plenty of sunshine and a high-potash feed.
When buds appear, apply tomato feed to the soil once a week for four weeks. “With a high potash feed, it encourages these flowers to get even bigger and even more abundant,” Ish said. After the first flowers fade, cut off the spent spikes and apply manure or slow-release fertiliser to promote a second bloom in summer.
Tomato feed is rich in potassium, which boosts flowering and fruiting, and also contains nitrogen, phosphorus, and magnesium for overall plant health. It helps protect against diseases and environmental stress. Prune wisteria alba in late winter, from January to February, to keep it under control.
